Description

Definition of kinematic boundary conditions. When referring to a local cylindrical coordinate system (csys${}{\mathrm{tr}}$), X corresponds
to the radial direction, Y to the tangential direction and Z to the axial direction.

The optional activation function is used to define more complex switches than
a simple activation/deactivation time. fid${}_n$ refers to the ID of a FUNCTION.
The prescribed motion (or rotation) is active if the specified FUNCTION returns a value > 0.

Example

Constraining rigid body with part

The following commands constrain the rigid body with part ID 333 in translation (all directions) and in rotation
around the global x- and y-axes. A prescribed spin (100 rad/s) is defined around the z-axis.
The title will show up in the ASCII file prescribed.out and helps the user
distiguish between different *BC_MOTION definitions in the input deck.

Constraints can be applied in a cylindrical coordinate system. The example below constrains the tangential motion of a node set.
The polar coordinate system has its center at (%xc, %yc, %zc) and its axial direction is (%xn, %yn, %zn). The tangential motion
of the nodes in the set is constrained by setting bc${}_{\mathrm{tr}}$=Z.